Systems and methods for intravascular obstruction removal

ABSTRACT

Intraluminal devices and methods for removing an obstruction from a blood vessel using an intraluminal device are provided. The intraluminal device can include a flexible shaft and an expandable wire mesh structure extending from the flexible shaft, the wire mesh structure including at least one first expandable section having a first wire arrangement pattern and at least one second expandable section having a second wire arrangement pattern different from the first wire arrangement pattern. In addition, interstices in the at least one first expandable section can differ in size from interstices in the at least one second expandable section.

PRIORITY

This application claims the benefit of priority from U.S. ProvisionalApplication No. 62/112,862 filed Feb. 6, 2015, the disclosure of whichis herein incorporated by reference in its entirety.

FIELD

This disclosure relates to intravascular and/or intraluminal medicaldevices and systems that are configured to retrieve an obstruction fromhuman blood vessels. The disclosure also relates to methods of removingan obstruction from human blood vessels.

SUMMARY

This disclosure describes an intravascular and/or intraluminal medicaldevice that may retrieve an obstruction from human blood vessels. Thisobstruction may be a blood clot (of embolic or thrombotic origin). Thedevice may be constructed from an expandable mesh structure extendingfrom an elongated shaft. The expandable mesh structure may utilizediffering wire arrangement patterns to create a structure with variableinterstices sizes and/or one or more expandable sections. As a result,when the device is expanded alongside or within a clot inside a bloodvessel, the clot may penetrate the mesh due to the large interstices,and then when the mesh is retrieved, the clot may be held in the mesh.In other words, when the mesh applies radial forces on the clot, it maypresent large enough openings to expand through the clot. In someembodiments, when the expanded mesh applies axial forces on the clot, itmay present small enough openings to hold the clot during clotretrieval. The wire arrangement patterns might be such that theinterstices in the distal and proximal ends of the mesh may be smallerthan at least some of the interstices that are more central. However,other arrangement patterns might also be used. For instance, the devicemay be made out of only two types of wire arrangement patterns, thedistal one with relatively smaller openings or interstices and theproximal one with relatively larger openings or interstices.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments and, together withthe description, serve to explain the features, advantages, andprinciples of the disclosed embodiments.

FIG. 1 depicts an expandable mesh structure with varying wirearrangements creating interstices of different sizes consistent with thedisclosure;

FIG. 2 depicts an alternative mesh arrangements of braiding and straightwires consistent with the disclosure;

FIG. 3 depicts an expandable mesh structure with alternating braided andintertwined wire couples consistent with the disclosure;

FIG. 4 depicts an expanded view of an intertwined section consistentwith the disclosure which creates larges interstices;

FIG. 5 illustrates a 1×1 braiding arrangement that transitions to a 1×3braiding arrangement consistent with the disclosure;

FIG. 6 illustrates another braiding arrangement consistent with thedisclosure;

FIGS. 7A-7F illustrate the components of braiding arrangement 7G withuniform interstices;

FIGS. 8A-8F illustrate the components of 1×1 braiding arrangement thattransitions to a 1×3 braiding arrangement (FIG. 8G) consistent with thedisclosure;

FIGS. 9A-9F illustrate the components of 1×1 braiding arrangement thattransitions to a 3×3 braiding arrangement (FIG. 9G) consistent with thedisclosure;

FIGS. 10A-10D illustrate the components of 1×1 braiding arrangement thattransitions to a 1×2 braiding arrangement (FIG. 10E) consistent with thedisclosure;

FIGS. 11A-11D illustrate the components of 1×1 braiding arrangement thattransitions to a 2×2 braiding arrangement (FIG. 11E) consistent with thedisclosure;

FIGS. 12A-12D illustrate the components of 2×2 braiding arrangement thattransitions to a 1×4 braiding arrangement (FIG. 12E) consistent with thedisclosure;

FIG. 13 illustrates an expandable mesh created from wires of a cabledshaft consistent with the disclosure; and

FIG. 14 illustrates a clot retrieval process consistent with thedisclosure.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to the one or more embodiments,characteristics of which are illustrated in the accompanying drawings.Wherever possible, the same reference numbers will be used throughoutthe drawings to refer to the same or like parts.

FIG. 1 depicts a mesh structure associated with expandable meshstructure 100. The mesh structure depicted in FIG. 1 includes withvarying wire arrangements, which can create interstices of differentsizes when the expandable mesh structure 100 is in an expanded state.For example, interstices 110 in expandable mesh structure 100 can belarger than interstices 105 in expandable mesh structure 100 whenexpandable member 100 is in an expanded state. In addition, the wires ofthe expandable mesh structure 100 can be used to create a cable shaft,such as cable shaft 90.

In some embodiments, the interstices in a first expandable section maydiffer in size from the interstices in a second expandable section by apredetermined amount. For example, the interstices in the secondexpandable section may be approximately three times, five times, tentimes, or twenty times larger than the interstices in the firstexpandable section.

It should be noted that this invention is not limited to a device withonly two wire arrangements; alternating wire arrangements can also beused to create a structure with varying sized openings. For instance,one embodiment of the device can be made of alternating braided wiresand a segment of straight or non-braided wires (FIG. 2). In thisstructure, the braided portion between the straight wire segments may bea stable piece that holds the wire arrangements together. In addition,it may create a border between the large openings. Specifically, FIG. 2depicts expandable mesh structure 200 with alternative mesharrangements. For example, region 215 of expandable mesh structure 200can include braided wires and region 220 of expandable mesh structure200 can include straight (or aligned, parallel) wires.

In yet another embodiment, a plurality of wires in the large intersticessection can be intertwined to create even larger openings. FIG. 3 is anillustration of an expandable mesh structure 300 in which each couple ofwires is intertwined between the braided sections and, as a result, thelarge openings are created. In this embodiment, the distal braidedsection also serves as a filter in case particles break off and flowdistally during the retrieval process. Specifically, in the embodimentdepicted in FIG. 3, expandable mesh structure 300 is shown with abraided region 324 that transitions to an intertwined region 331 (withintertwined wire couples), and then is shown as transitioning (oralternating) back to a braided region 326. The interstices 325 can besmaller than the interstices 330 when expandable mesh structure 300 isin an expanded state.

FIG. 4 depicts a close-up view of expandable mesh structure 400 (when inan expanded state). As shown in FIG. 4, interstices 440 (associated witha region of intertwined wires) can be larger than interstices 435(associated with a braided arrangement).

Furthermore, other braiding patterns can be utilized to create thedifferent interstices. For example, 1×1 (one wire over one wire) can beused for the small dense section and 3×1 (3 wires over 1 wire) can beused in the larger interstices section (FIG. 5). Other braiding examplesare, but are not limited to, 2×2 (two wires over two wires) combinedwith three intertwined wires, or 2×2 combined with 4×1 or 1×1 combinedwith 3×3 (FIG. 6).

More specifically, FIG. 5 depicts an expandable mesh structure 500 whichincludes a 1×1 braiding arrangement (in region 545) that transitions toa 1×3 braiding arrangement (in region 550). As shown in FIG. 5, theinterstices in region 550 can be larger than the interstices in region545. FIG. 6 depicts an expandable mesh structure 600 which includes a1×1 braiding arrangement throughout; however the interstices in region660 can be larger than the interstices in region 655 when expandablemesh structure 600 is in an expanded state.

FIG. 7 depicts pairs of continuous braided wires (pair 701 in FIG. 7A,pair 711 in FIG. 7B, pair 721 in FIG. 7C, pair 731 in FIG. 7D, pair 741in FIG. 7E, and pair 751 in FIG. 7F) that, together, make up the braidwith uniform interstices 765 depicted in expandable mesh structure 700(FIG. 7G). In an expanded state, the expandable mesh structure 700includes a hollow region (shown as cylindrical in FIG. 7). The dashedlines in FIG. 7 (and in FIGS. 8-12) correspond to that portion of acontinuous wire that falls “behind” the hollow portion (when viewed fromthe “front” as shown in FIG. 7).

FIG. 8 depicts pairs of continuous braided wires (pair 802 in FIG. 8A,pair 812 in FIG. 8B, pair 822 in FIG. 8C, pair 832 in FIG. 8D, pair 842in FIG. 8E, and pair 852 in FIG. 8F) that, together, make up the 1×1braiding arrangement that transitions to a 1×3 braiding arrangementdepicted in the expandable mesh structure 800 of FIG. 8G. As shown inFIG. 8G, interstices 870 can be larger than interstices 765 whenexpandable mesh structure 800 is in an expanded state.

FIG. 9 depicts pairs of continuous braided wires (pair 901 in FIG. 9A,pair 913 in FIG. 9B, pair 923 in FIG. 9C, pair 933 in FIG. 9D, pair 943in FIG. 9E, and pair 953 in FIG. 9F) that, together, make up the 1×1braiding arrangement that transitions to a 3×3 braiding arrangementdepicted in the expandable mesh structure 900 of FIG. 9G. As shown inFIG. 9G, interstices 980 can be larger than interstices 765 whenexpandable mesh structure 900 is in an expanded state.

FIG. 10 depicts pairs of continuous braided wires (pair 1004 in FIG.10A, pair 1014 in FIG. 10B, pair 1024 in FIG. 10C, and pair 1034 in FIG.10D) that, together, make up the 1×1 braiding arrangement thattransitions to a 1×2 braiding arrangement depicted in the expandablemesh structure 1000 of FIG. 10E. As shown in FIG. 10E, interstices 1090can be larger than interstices 1085 when expandable mesh structure 1000is in an expanded state.

FIG. 11 depicts pairs of continuous braided wires (pair 1106 in FIG.11A, pair 1116 in FIG. 11B, pair 1126 in FIG. 11C, and pair 1136 in FIG.11D) that, together, make up the 1×1 braiding arrangement thattransitions to a 2×2 braiding arrangement depicted in the expandablemesh structure 1100 of FIG. 11E. As shown in FIG. 11E, interstices 1191can be larger than interstices 1085 when expandable mesh structure 1100is in an expanded state.

FIG. 12 depicts pairs of continuous braided wires (pair 1207 in FIG.12A, pair 1217 in FIG. 12B, pair 1227 in FIG. 12C, and pair 1237 in FIG.12D) that, together, make up the 2×2 braiding arrangement thattransitions to a 1×4 braiding arrangement depicted in the expandablemesh structure 1200 of FIG. 12E. As shown in FIG. 12E, interstices 1191can be larger than interstices 1292 when expandable mesh structure 1200is in an expanded state.

In yet another embodiment, the larger interstices can be created bykeeping the same general wire arrangements (for instance one over one)but by changing the angle of the intersection. In yet another option,the large interstices can be achieved by reducing the number of wires atsome portion of the arrangement (for instance, by terminating a numberof the wires at the end of the first section).

Further, in some embodiments, each of the expandable sections may beconfigured to expand to different outer diameters. For example, a firstexpandable section may be configured to expand to an outer diametersmaller than the outer diameter of the second expandable section whenthe second expandable section is expanded. That is, when each of thesections of the device is expanded, the device may have multiple,different outer diameters along the length of the device.

Additionally, the expandable sections having different expanded outerdiameters may be arranged in any desired order with respect to oneanother along the length of the device. For example, in one embodiment,a first type of expandable section may be located between a plurality ofexpandable sections of a second type. This arrangement may result in anexpandable structure with at least two peaks and one valley. However,other arrangements may result in an expandable structure with otherquantities of peaks and valleys formed as a result of the differentdiameters of the expandable sections. By way of example only, there maybe three valleys and two peaks, or four valleys and three peaks. Moregenerally, there may be one more valley than there are peaks. Or therecould be an equal number of peaks and valleys. Or, there could be onemore peak than there are valleys.

Moreover, the single wires can differ from each other in theircharacteristics; material, diameter, shape, cross-sectional shape,radio-opacity, etc. For instance, one Platinum wire can be used to makethe structure visible under fluoroscopy while the other wires can be ofless visible materials, such as Nitinol. In different embodiments,polymer wires can be combined with metal wires to achieve the requiredmechanical properties of the structure. In addition, flat wire might beused to lower the overall profile of the device or round wires can beused for better kink resistance. Nonetheless, the disclosure above canincorporate any types of wires from any materials, sizes and shapes. Inaddition, the wires might be coated or covered. A coating might bedesirable to ease the delivery of the structure through a tightmicro-catheter. In addition, the wires might be drug coated to affect atreatment or to increase adherence to the clot. Finally, the section ofthe small interstices might be covered with an outer polymer or othercovering to allow even greater protection against distal shower.

The expandable mesh may also be extended from an elongate shaft. Theshaft may be long enough to deliver and control the mesh from outsidethe body. The shaft might be made of a stiff portion to enhancepushability and stability on its proximal part, and a flexible portionon its distal part. The distal part may be connected at its distal endto the expandable mesh. The proximal stiffer part can be produced from ahollow metallic tube or from a reinforced polymer structure. The distaland/or proximal part might be also created from a reinforced polymerstructure of a more flexible nature. In addition, it might be createdfrom a cut metallic tube. Moreover, it may be created like a cable, forexample, from strands of wires arranged in a coiled assembly. If thelatter cable-like assembly is utilized, the wires of the cables can alsobe used to create the expandable mesh structure. In this case, a bondbetween the shaft and the expandable portion may not be necessary. As aresult, the device can be made very flexible, thus simplifying theassembly process (FIG. 13). Specifically, FIG. 13 illustrates expandablemesh 1300 created from wires of a cabled shaft (such as shaft 90).

There are different ways to expand the expandable mesh member that isextended from the shaft described above. One possibility is to make itself-expanding by setting its structure in the expanded shape. This canbe achieved via heat treatment if the device is made of metallic wiressuch as Nitinol.

Another alternative is to use one or more pull or control wires that canbe connected to the expandable members. These wires may extend throughthe flexible portion of the shaft to the proximal portion of the shaftand, when a force is exerted on the pull or control wire (e.g., a pullforce), the mesh member may expand. In one embodiment, only one corewire may be used and connected to the expandable member at its distalend. In this case, the wires of the expandable member might terminate ina coiled structure. The pull wire may be connected to the coiledstructure at the distal part of the expandable member. When the pullwire is pulled, it may expand all of the wires of the expandable memberand thereby expanding the expandable member. In addition, the wires ofthe expandable member can terminate in other fashions. For example, theycan be arranged in parallel at the distal end. In yet anotherembodiment, one or more of the wires can be curved back and used as pullwires themselves.

In some embodiments, the pull wire alternative may have some advantagesover the self-expanding one. First, the amount of expansion might becontrolled by use (the more pulled, the more expansion at the distalend) unlike the self-expanding option which may be pre-set. This can bebeneficial if, for example, the clot is retrieved through blood vesselsof varying diameter. In addition, since the device may be delivered inan unexpanded state, delivery through a tight micro-catheter might beeasier. Yet an additional alternative for expansion of the expandablemember is to use temperature changes or to utilize currents that willcause metallic wires to change their mechanical properties.

As mentioned above, the device disclosed may be used to remove anobstruction from a vessel. This obstruction may be a blood clot ofdifferent origins but is not limited to such. For instance, theobstruction can also be plaque of foreign bodies. Or the device may besized for use in a conduit other than a blood vessel.

One embodiment of a method for removing an obstruction from a vesselwith the disclosed device may include inserting the device having theexpandable structure into the vessel. The expandable section may includeat least one end region having interstices that are at least three timessmaller in size than interstices in a central region. The expandablestructure may then be positioned in a desired location. For example, theexpandable structure may be moved so that at least the central regionthat coincides with the obstruction (e.g., is aligned with, alongside,fully within, or partially within the obstruction). Once aligned, theexpandable structure may be expanded, for example, by using the pull orcontrol wire, to embed some or all of the obstruction in the centralregion. The expandable structure containing the embedded obstruction maythen be withdrawn from the vessel.

One implementation of the embodiment of the method for removing theobstruction from the vessel is illustrated in FIG. 14. However, itshould be noted that while the method is illustrated in the context ofclot removal from brain blood vessels, in other embodiments, the devicemay be used to remove a variety of other types of obstructions as well.In one embodiment, the method of use for the device may include one ormore of the following:

-   -   1) The clot location may be identified using imaging. For        example, FIG. 14A depicts clot 1408 in blood vessel 1409, where        clot 1408 obstructs blood flow.    -   2) Using minimally invasive catheterization techniques, an 8 Fr        guide catheter may be placed at the internal carotid artery.    -   3) A 3 Fr micro-catheter guided by a guidewire may be placed        across the clot (the micro-catheter tip may be distally located        with respect to the clot). As shown in FIG. 14B, micro-catheter        1415 can be advanced into blood vessel 1409 to the location of        clot 1408 such that the opening of micro-catheter 1415 is on the        distal side of clot 1408.    -   4) The guidewire may be removed while the micro-catheter remains        in place.    -   5) The expandable member may be advanced through the        micro-catheter. The shaft may be used to advance the expandable        mesh to the micro-catheter tip. For example, an expandable        member 1417 (in an unexpanded state) can be delivered through        micro-catheter 1415 as shown in FIG. 14C to clot 1408.    -   6) The micro-catheter may be pulled back while the expandable        member remains in place (its tip distal to the clot) and, as a        result, the expandable member may be unsheathed alongside the        clot.    -   7) The pull wire may be pulled to expand the expandable member.        The user may choose the amount of expansion necessary to        penetrate the clot. For example, expandable member 1417 can be        expanded though clot 1408 as shown in FIG. 14D.    -   8) The balloon guide catheter may be inflated, and the guide        catheter may be aspirated to reverse the blood flow.    -   9) Both micro-catheter and the expandable member may be        retrieved. The user might need to expand the expandable member        when the device is pulled through larger vessels. The expandable        member and micro-catheter may be retrieved through the guide        catheter. As shown in FIG. 14E, expandable member 1417 and clot        1408 can then be retrieved.

In addition to the method of use described above, the expandable membercan also be used to retrieve additional foreign materials from thebodily lumens. For example, it can also be used to retrieve pulmonaryembolism, kidney stones, etc.

Further, in some embodiments, the device may include a flexible shaftmade of 12 wires. In such embodiments, 6 of the wires may be arranged ina clockwise direction, and the other 6 may be arranged in acounterclockwise direction.

In some embodiments, the non-braided section of the expandable membermay include intertwined pairs.

In some embodiments, the wires substantially do not cross in thenon-braided section of the expandable member.

In some embodiments, different types of braiding may be employed in sameexpandable member.

The following terminology descriptions are exemplary, and notrestrictive of embodiments of the invention, as described above.

An intraluminal device (or intraluminal expandable member) includes anyexpandable member that may be inserted into a lumen, conduit, or vessel.

A wire mesh structure includes any structure made at least wholly orpartially from wire, regardless of whether the structure is made frommetal, polymers, or any other material.

A wire arrangement pattern is a configuration of wires. In its broadestsense, the pattern does not have to have any measure of regularity. Insome embodiments, the configuration may include repetition, in othersthere may be no repetition.

Interstices include any intervening space, including, for example, anyform of gap, space, hole, interval, or slit.

A braid is a configuration of a plurality of strands with diagonaloverlaying or overlap, such as in a weave or interlacing.

What is claimed is:
 1. An intraluminal device, comprising: a flexibleshaft comprising multiple strands of wires; an expandable wire meshstructure formed from the multiple strands of wires and extending fromthe flexible shaft, the wire mesh structure including at least one firstexpandable section having a first wire arrangement pattern and at leastone second expandable section having a second wire arrangement patterndifferent from the first wire arrangement pattern; and a control wireextending through the flexible shaft and the expandable mesh structure,the expandable mesh structure being configured to enable a force exertedon the control wire to expand the mesh structure; wherein the at leastone second expandable section includes at least two non-braided sectionsseparated by a braided section; wherein interstices in the at least onefirst expandable section differ in size from interstices in the at leastone second expandable section.
 2. The intraluminal device of claim 1,wherein at least a portion of the wire of the at least one firstexpandable section is braided.
 3. The intraluminal device of claim 2,wherein interstices of the at least one second expandable section arelarger than interstices of the at least one first expandable section. 4.The intraluminal device of claim 2, wherein the at least one firstexpandable section includes at least two braided sections separated by anon-braided section.
 5. The intraluminal device of claim 1, whereininterstices in the at least one second expandable section are at leastthree times larger than interstices in the at least one first expandablesection.
 6. The intraluminal device of claim 1, wherein interstices inthe at least one second expandable section are at least five timeslarger than interstices in the at least one first expandable section. 7.The intraluminal device of claim 1, wherein the at least one secondexpandable section has interstices larger than interstices of the atleast one first expandable section, and wherein the wire mesh structurehas the pattern of the first wire arrangement pattern on opposingproximal and distal ends thereof.
 8. The intraluminal device of claim 1,wherein the multiple strands include wires having differingcross-sectional shapes.
 9. The intraluminal device of claim 1, whereinthe multiple strands include wires of differing material.
 10. Theintraluminal device of claim 1, wherein the multiple strands include atleast one wire having a radio-opacity that differs from a radio-opacityof at least one other of the plurality of wires.
 11. The intraluminaldevice of claim 1, wherein interstices in the at least one secondexpandable section are at least ten times larger than interstices in theat least one first expandable section.
 12. The intraluminal device ofclaim 1, wherein interstices in the at least one second expandablesection are twenty times larger than interstices in the at least onefirst expandable section.
 13. An intraluminal device, comprising: aflexible shaft comprising multiple strands of wires; and an expandablewire mesh structure formed from the multiple strands of wires andextending from the flexible shaft, the wire mesh structure including atleast one first expandable section having a first wire arrangementpattern and at least one second expandable section having a second wirearrangement pattern different from the first wire arrangement pattern;wherein the at least one second expandable section includes at least twonon-braided sections separated by a braided section; wherein intersticesin the at least one first expandable section differ in size frominterstices in the at least one second expandable section; and whereinwhen expanded, the at least one second expandable section has an outerdiameter greater than an outer diameter of the at least one firstexpandable section.
 14. The intraluminal device of claim 13, wherein theat least one second expandable section includes a plurality of secondexpandable sections with at least one of the at least one firstexpandable sections located therebetween, resulting in an expandablestructure with at least two peaks and one valley.
 15. The intraluminaldevice of claim 13, wherein the at least one first expandable sectionincludes a plurality of first expandable sections, and wherein the atleast one second expandable section includes a plurality of secondexpandable sections, and wherein each second expandable section isinterposed between two first expandable sections, resulting in anexpandable structure with a plurality of peaks and a plurality ofvalleys.
 16. A method of removing an obstruction from a vessel, themethod comprising: inserting, via a flexible shaft comprising multiplestrands of wires, into the vessel an expandable structure formed fromthe multiple strands of wires that when expanded, has at least one firstexpandable section having a first wire arrangement pattern and at leastone second expandable section having a second wire arrangement patterndifferent from the first wire arrangement pattern, wherein the at leastone second expandable section includes at least two non-braided sectionsseparated by a braided section; moving the expandable structure so thatat least the second expandable section coincides with the obstruction;expanding the expandable structure, via a control wire extending throughthe flexible shaft and the expandable mesh structure, the expandablemesh structure being configured to enable a force exerted on the controlwire to expand the mesh structure, to embed at least a portion of thesecond expandable section within the obstruction; and withdrawing fromthe vessel the expandable structure containing the embedded obstruction.17. The method of claim 16, wherein the expandable structure includes aplurality of sections having differing wire arrangement patterns. 18.The method of claim 17, wherein at least one wire arrangement pattern ofthe expandable structure is braided and at least one wire arrangementpattern of the expandable structure is non-braided.
 19. The method ofclaim 16, wherein the interstices in the at least one first expandablesection are at least five times smaller than interstices in the secondexpandable section.
 20. The method of claim 16, wherein wire of the atleast one first expandable section is braided and wire of at least aportion of the at least one second expandable section is unbraided. 21.An intraluminal device, comprising: a flexible shaft; an expandable wiremesh structure extending from the flexible shaft, the wire meshstructure including at least one first expandable section having a firstwire arrangement pattern and at least one second expandable sectionhaving a second wire arrangement pattern different from the first wirearrangement pattern; and a control wire extending through the flexibleshaft and the expandable mesh structure, the expandable mesh structurebeing configured to enable a force exerted on the control wire to expandthe mesh structure; wherein the wire mesh structure transitions from theat least one first expandable section to the at least one secondexpandable section along the length of the device; and wherein at leasta portion of the wire of the at least one first expandable section isbraided and at least a portion of the wire of the at least one secondexpandable section is non-braided; and wherein the at least one secondexpandable section includes at least two non-braided sections separatedby a braided section.
 22. An intraluminal device, comprising: a flexibleshaft; an expandable wire mesh structure extending from the flexibleshaft, the wire mesh structure including at least one first expandablesection having a first wire arrangement pattern and at least one secondexpandable section having a second wire arrangement pattern differentfrom the first wire arrangement pattern; and a control wire extendingthrough the flexible shaft and the expandable mesh structure, theexpandable mesh structure being configured to enable a force exerted onthe control wire to expand the mesh structure; wherein the wire meshstructure transitions from the at least one first expandable section tothe at least one second expandable section along the length of thedevice; wherein at least a portion of the wire of the at least one firstexpandable section is braided and at least a portion of the wire of theat least one second expandable section is non-braided; and wherein theat least one second expandable section includes a plurality ofnon-braided sections, each disposed between two braided sections.